Special interests are physiological ecology and invertebrate physiology and biochemistry of freshwater and terrestrial molluscs and freshwater crustaceans -- most recently we have been studying the mechanism of calcium carbonate deposition in clam, crayfish, lobster, and crab shell. Calcium and strontium in shell formation have also been studied in both snails and ostracods. The phylogeny of both wild rice and phyllopods are also areas of interest.